Category Archives: Cameras

Still life successes

Using my antique (1900s) large format (10×8) bellows field camera I have been making some successful still life images.

I decided to move away from the uncontrolled variable light of the kitchen window to the fixed lights in my studio (dining room). This removed one variable from the exposure equation allowing me to make reliable test exposures on strips of the photo paper negative I am using. This saves the expense of wasting large sheets of photo paper on improperly exposed shots.

Whilst I am pretty happy that I can measure the light needed with my iphone app based on iso 6 for the paper negative, there are three other variables that come in to play.

1. At larger f stop values (smaller holes in the diaphragm) a small variance in position of the lever or ring setting the aperture has a disproportionately greater effect on the actual aperture used – at f64 on one lens a small tweak can make it effectively nearer f128 – doubling the required exposure time!

2. The bellows effect. Stretching the bellows past the focus length of the lens for close objects decreases the light intensity falling on the negative by an inverse square proportion. Doubling the distance decreases light intensity to a quarter. So 4x the exposure time is needed.

3. At longer exposure times, the longer the exposure the longer you need to achieve a set increase in darkening of the negative. So for a 2 minute calculated exposure I would expose for 2.3 minutes.

With these variables in play it pays to take a test exposure on strip of photo paper before committing to exposing a whole sheet.

For many of the still life images I am using a shorter (8″) focus length lens as this gives the greatest magnification. However it only stops down to f22,rather than the f64 of my other lenses, thus limiting the depth of field achievable. Accepting this limitation I have chosen subjects which do not demand a great depth of field – and am very pleased with the results.

I also added a graduated neutral density filter for the fennel photo to darken the bright base to get a more evenly exposed picture which seemed to work (see bottom photo).

Lens problems with The New Countess

Today was time to take the New Countess full plate camera to Clevedon and try some images of the wonderful Victorian Pier. Shame it was so breezy – not ideal for longish exposures with a huge camera like this one!

With two slides I had 4 exposures to make. It was a good opportunity to try the (supposedly) F384 lens too as it was a good focus length (12 inches – 300mm ) for the job.IMG_2026

Bringing the exposed paper negatives home for developing, I found that the lens I was using – Rapid Aplanat No.3 Ser.D.F.8 (R.O.J.A. vorm. Emil Busch, Rathenow) – was not operating at the indicated F stops – see the title image!

I had tested it in the garden on the pear tree using the widest aperture with no problem – but at the indicated f90 it way over-exposed the image (Paper negative). I tried a couple of other lenses at the same time successfully so thought I’d make some measurements of the diaphragm aperture with digital callipers and calculate the theoretical f-stop  (dividing the focal length by the aperture diameter)

As the F stop numbers increase the variance between the indicated F stop and the calculated one increases greatly. Column headings are Focul length, Diameter (of aperture) in 100ths of an inch, The F stop indicated and the F stop calculated.

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Using a more familiar lens at F45 for a 2 second exposure I achieved a reasonable if (wind) shaken exposure.

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Large Format Portrait – Artificial Light

With its custom replacement glass screen fitted (https://www.ebay.com/usr/virgisst ) I have made some further tests of the recently acquired full plate (10×8 inch) camera (The New Countess). I wanted to test how well the camera could be used with artificial lights since the paper negative responds differently to film.

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My first shot was with a short focus length f6.3 lens and an exposure time of 2 seconds. With two large fluorescent bulb lamps, this produced a well-exposed image but the depth of field was very short. To gain depth of field I changed to a lens that went to F64, with a much longer focus length.

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However the sliding control moves past the “64” and my first images were way under exposed as the aperture was much less than for F64.

Further test strips gave me an exposure time of 35 minutes. Below are two images; F22 on the left, F64 (+) on the right. The difference in depth of field is evident.

Clearly a 35 minute exposure isn’t appropriate for portraiture. So extra illumination is needed to keep depth of field as great as possible. There is no real substitute for daylight!

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Progress with the New Countess

A windless, bright day meant I could take the Countess into the garden and learn more about how it performs.

Successful experiments with low light and hight contrast situations have been encouraging. Focal lengths from 4 to 10 inches were tried with F stops from F6.3 to F45.

Exposure times ranged from 2 to 10 seconds.

However focussing is still difficult – I was waiting for a replacement screen that arrived a day later.
Here are pictures to show the difference in screen thickness.

Progress with The New Countess – 10×8 Camera

With some decent weather I have been able to take the “New Countess” into the garden and make some more trial images, testing out the lens and the exposure time variation with extending the bellows.

I am pleased to find that the combination of light metering with the I-phone app “Light & Exposure Meter” and adjusting for the bellows extension using measurements from “QuickDisc” (www.salzgeber.at/disc/)I was pretty successful with the images I made today. As always I like to push to the extremes – so after the pears image, some extreme contrasts with bright white table and chairs and then deep shadow for the surround of the bust.

I clearly have some work to do on managing the higher contrasts. I think I might have to expose for less and develop for more time. Anyway I am so pleases with the look and feel of these images from this camera. The Pears were shot at f11 and the table & chairs at f22. The bust was also f22 as I wanted to have a greater depth of field, but this wasn’t as deep as I had hoped – so will try again with f64.

NB – The images displayed here were made as paper negatives then digitised and made positives in Photoshop. The glossy Ilford paper was treated ISO6 and pre-flashed with an enlarger to reduce contrast.

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Going “large”

I have enjoyed learning to use my 1900s halfplate (5×7) camera and love the images it can produce. However, starting with a piece of paper negative that size means the mounted image is less than 5×7. This means I can’t enter it for camera club competitions. The 5×7 size is a little too small also for selling as wall art – unless arranged with other images.

Having tried 10×8 photography using my cardboard cameras and being satisfied with the results I decided that it was time to “go large”.

So I have purchased via eBay a 10×8 full plate camera of a similar vintage, ( I sold on one of my two 5×7 cameras first). With apparently good examples going for £800, I was pleased to get an offer accepted on one in OK condition for less than half that price.

This camera has bellows in great condition, but needed some light repairs to splits and breaks in the wooden structure and mounting points. I use “chair repair” runny PVA glue to get into the cracks and clamp overnight to effect these repairs.

The metal parts on this “New Countess” are aluminium rather than brass. Some of these parts needed straightening which was a tense but successful process.

With a good dousing of leather “reviver” on the bellows and a cautious sprinkling of graphite powder on the sliding surfaces much of the renovations have been done.

Some home-made PVA and sawdust filler were needed to fill a light-leaking crack in one of the two film slides.

The lens that came with the camera is an F11 10 inch focus length example with a rotating disc of aperture holes. F11 is a bit restrictive so I have made some additional lens boards to fit, using the original one as my pattern. I can now use any of my lenses with this camera, including the Thornton Pickard shutter for short exposures.

The last modification to the camera was to make a strong tripod mount from a disc of 12mm plywood and sunken bolt-screw arranging to take a standard tripod screw.

I taped strips of photographic paper to the slides in order to test the camera and was pleased to find no light leaks from the camera and only the cracked slide needing additional repair. Now happy with the camera I ran three test shots with some 10×8 sheets of photographic paper. I pre-flash the paper to reduce the contrast and for the first shot I over did this so the whole sheet was dark. The next two shots were much better. At this point I was having to guess the F stop as I hadn’t seen the indistinctly scratched numbers on the F-stop disc. Therefore the exposures are a little dark,

The glass focussing screen is not original and quite a thick and murky piece of glass – hard to use. So I have ordered a replacement to be made ( https://www.ebay.com/usr/virgisst ).

DIY Cardboard Camera Mk2

After some success with the first cardboard box camera, and wanting to produce some large format (10×8 inch) images, I set about designing and building a new camera which could focus the image without being moved. This has the great advantage of being able to adjust the size an object appears in the image and still be in focus.

To achieve the variable focus I produced a box in two parts so that one slid inside the the other and joined them together, in a light-tight fashion, with a piece of black polythene bin liner. This give a light-tight but flexible join. I used the same film holder from the first camera with some improvements to make it more light tight. I added a channel to the new camera within which the film carrier could slide, using a strip of black paper to provide a flexible, light tight seal between the carrier and the box camera. The carrier is inserted in the top of the box.

As usual here, I am using Ilford glossy photo paper – at ISO6 and pre-flashing it to decrease contrast.

Utilising a spare vintage lens I ran a few test strips because even though the lens has marked F-stops, the distance between the lens and the film also affects light intensity. After running the tests I made the first 10×8 image (F22 2s exposure). This was in intense bright sunlight – not the best for a good tonal range – but it did really test the light-tightness of the camera. Here is an iphone shot of the negative a digitally produced invert to create the positive image. Once the negative is dry, I’ll take a high resolution photograph of it.

This works! – I am getting the tonal range and soft-dreamy look I am after – for a lot less money than the £800 10×8 antique camera on Ebay I’ve been considering.

Next step is to wait for a softer light and make some more images.